This invention relates generally to apparatus for marking the lateral limit of an agricultural implement to indicate to a farmer where to position his tractor and is particularly directed to a folding row marker for use during planting.
Multi-section toolbars for use in agricultural applications generally include first and second wings pivotally mounted to a main, or center, frame. The wings or "bars" are pivotable between a use position in which the wings are oriented generally horizontally and extend laterally with respect to the main frame and transverse to the direction of travel of the vehicle which draws the toolbar, and a transport or storage position in which the wings extend either rearwardly of the main frame and parallel to the direction of travel of the vehicle or are folded upward so that the width of the entire retracted mechanism is no longer than the length of the main frame. Each of the toolbar wings is typically coupled to the main frame of the toolbar by means of a hinge mechanism which is aligned either vertically or horizontally to allow the wing to pivot in either one or the other of these directions. The present invention is intended for use with a multi-section toolbar in which the wings pivot vertically between the use and non-use positions.
During planting, a plurality of planter units are attached in a spaced manner to the toolbar along the length thereof. Recent trends in planter design and operation are toward the use of larger planters, with the planter frame extending as much as 80 feet in length in some cases. When making a pass with a planter of this length, the outermost planter units are spaced approximately 40 feet from the centerline of the tractor. Markers typically in the form of a disc are used as an aid to the farmer for proper positioning of his tractor. Regardless of the distances involved, the marker which establishes the position of the outermost row should have a length, in the use position, equal to one-half of the width of the planter frame when it is extended, i.e., the distance from the center line of the tractor to the outermost planting unit.
In the past, most row markers have included either a single arm pivotally coupled to an end of a planter frame or two arms pivotally joined together and having a marker element on the outboard end of one of the arms, with the inboard end of the other arm pivotally connected to the end of the planter frame. With the increasing size of planter systems, the tendency today is toward the use three-section row marker units to accommodate the larger planter systems. Examples of two-section row markers can be found in U.S. Pat. Nos. 3,766,987 to Orthman; 3,666,019 to Yeske; and 4,526,235 to Kinzenbaw.
Three-section, row marker systems provide the obvious advantage of increased field coverage over that of two-section row markers. Folding row markers also permit the marker arms to be folded in a more compact configuration thus limiting the height of the folded planter frame to facilitate non-use transport and reduce row marker storage space. An example of a folding row marker arrangement can be found in U.S. Pat. No. 4,207,950, also to Kinzenbaw. In general, prior art folding row marker arrangements are maintained in the retracted position by gravity. This does not generally result in the most compact storage configuration, nor are the various sections securely maintained in position by means of an applied force during transport.
The present invention is directed to a folding row marker for use with either a folding or a fixed toolbar in which a positive force is applied to the row marker when in the folded, non-use position for more secure and stable transport and storage of the toolbar and row marker combination.